Video communications systems are continually being enhanced to meet requirements such as reduced cost, reduced size, improved quality of service, and increased data rate. Many advanced processing techniques can be specified in a video compression standard, but the design of a compliant video encoder is not typically specified in the standard. Optimization of the communication system's requirements is dependent on the design of the video encoder, and an important aspect of the encoder design is rate control.
A video encoder that utilizes a constant quantization resolution for every block tends to under-allocate bits in areas that are well predicted and perceptually significant. While, a video encoder that uses the same number of bits for every macroblock tends to under-allocate bits to complex areas (high motion) such that a blocking artifact becomes noticeable. Rate control systems may attempt to choose a quantization level to balance between perceptually significance and complexity while maintaining the desired bit rate.
Limitations and disadvantages of conventional and traditional approaches will become apparent to one of ordinary skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.